Mixed mullerian tumor (MMT) is a biphasic malignancy of elderly women. It, including both a carcinomatous and a sarcomatous component (CC and SC), is regarded as a female genital tract carcinosarcoma (FGTCS). Since current methods to grade CC and SC are not still univocal, the authors estimate mitotic index (MI) and MIB 1-immunolabeling index (MIB 1-LI) as common prognostic indices for the MMT components. They also compare above prognostic indices with p-53 immunocytochemistry, in MMTs. The present study thus points out that: (a) MI of CC and SC areas is consistent with the respective conventional tumor grades; (b) MI averages of CC are higher than those observed in the SC areas; (c) MI and MIB 1-LI of the CC-tumor cells correlate reciprocally in a very significant fashion; (d) A diffuse strong p53 nuclear immunostaining (> 50% cells) is often patent where the highest MI and MIB 1-LI are found. In conclusion, the authors propose MI and MIB 1-LI as two complementary useful indices to assess prognosis of MMTs. They also suggest p53 nuclear immunolabeling should be regarded as an independent biomarker of unfavourable MMT behaviour.